From hundreds of deaths to revelations about the nefarious White Walkers to new alliances, Season 6 was incredibly dense. If you don’t have time to catch up on the most-recent season before Sunday’s big premiere, here are six key points you should remember.

1. Many, many characters were killed

Was the sixth season the deadliest in the series’ history? It depends on how many nameless and faceless casualties you count, but the writers certainly dispensed with many of the antagonists over the course of 10 episodes, many in the deadly season ender.

In that finale, Margaery, her brother Loras, fundamentalist leader the High Sparrow, Lannister relatives Kevan and Lancel, and more were killed in the explosion at the Sept, Septa Unella was contained for her long punishment from Cersei and King Tommen committed suicide. Jon and Sansa dealt with Ramsay in the Battle of the Bastards (who killed his own villainous father earlier in the season). The Blackfish was last seen defending the Tully family seat at Riverrun. Dany killed a group of Khals in the East, as well as two of the three Wise Masters of Slaver’s Bay that had been plaguing her. Arya killed the Waif , her nemesis from the House of the Black and White, and later Walder Frey, the architect of the Red Wedding.

2. Jon, Cersei and Daenerys are left with the most power

Lena Headey as Cersei Lannister in 'Game of Thrones'

With all those players taken off the board, the game of thrones has gotten much smaller. Jon was declared King in the North after he successfully took Winterfell back from the Boltons. After the Sept explosion and Tommen’s suicide, Cersei was crowned Queen of the Seven Kingdoms, unopposed. Dany managed to ally herself with the grieving Olenna Tyrell, the Sand Snakes of Dorne and Yara and Theon Greyjoy, while gaining a new army after burning Vaes Dothrak to the ground.

There’s one more pesky wannabe king that could cause problems: their uncle Euron. He won control of the Iron Islands over Yara at the Kingsmoot midway through the season and wanted to ally himself with Dany. Yara and Theon got there first (using his ships), but Euron is still alive and potentially a threat.

3. Bran has time-traveling ability and already changed the past

Jon Snow is born in a vision from the past in 'Game of Thrones' Season 6. (Photo: HBO)

After a certain Season 6 episode, we were never able to think of the phrase “hold the door” in the same way again. We discovered Bran has more powers than we knew, such as visiting the past. At first, he appeared to just be an observer, but a fateful encounter with Hodor’s past and present revealed that he could change it.

In the finale, Bran witnessed the birth of Jon, who is revealed to be the son of Ned's sister Lyanna Stark (who dies soon afterward) and Rhaegar Targaryen, making him Dany’s nephew, Sansa’s cousin, and potentially the strongest claimant to the Iron Throne (although still a bastard). Bran, who is now the mythic Three-Eyed Raven, is the only person who knows this, it seems.

4. Some characters are MIA

Rory McCann as the Hound in 'Game of Thrones' Season 6. (Photo: HBO)

Brienne of Tarth and her trusty squire Podrick Payne have not been seen since the eighth episode of Season 6, when they rowed away from Riverrun after Jaime took the keep. They were presumably headed back North to reunite with Sansa, as Brienne became her sworn shield at the beginning of the season. (Glimpses of actress Gwendoline Christie were seen in the North in first-look photos from Season 7).

Also missing is Melisandre, whom Jon banished from the North after her part in burning Shireen at the stake came to light, and the Hound, who got off the bench after his idyllic retirement to a community of do-gooder peasants was violently ripped away from him. His reappearance reminds us that Beric Dondarrion and the Brotherhood Without Banners — the men who tried to protect bystanders from becoming casualties of the warring great houses — are still around.

5. Everyone else is a wildcard

Arya (Maisie Williams) in 'Game of Thrones' Season 6. (Photo: HBO)

What happens in Game of Thrones when you’re not one of the major players anymore? That’s the question Arya, Sansa, Jaime and Littlefinger will confront in the new season.

When we last saw Arya, she was finally back in Westeros and she had crossed off another entry on her vengeance to-do list. Sansa was present for Jon’s ascendancy to King in the North, but Littlefinger was whispering in her ear again and she seemed a tad resentful when he didn't share credit. Jaime, too, was not overjoyed at Cersei’s coup d’etat, possibly because she unleashed the wildfyre he tried to prevent the Mad King from using so many years before.

6. The White Walkers are still a huge problem

The White Walkers attack in 'Game of Thrones' Season 6. (Photo: HBO)

In the excitement of Cersei’s coup and Dany’s voyage, it may have been easy to forget that the White Walkers are looming behind the Wall. We learned, with the reappearance of Benjen Stark, that the White Walkers can’t cross it, because of the ancient magic within it. Sam and Gilly went to Oldtown to learn more about them, and Sam gained a Valyrian steel sword along the way — one of the few weapons that will kill a White Walker. Jon and Brienne also have Valyrian swords.

We also learned, during one of Bran’s trips to the past, that the ancient Children of the Forest created the White Walkers as a weapon to fight man. It worked a little too well.